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The nature of ionized gas in early-type galaxies

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 نشر من قبل Francesca Annibali
 تاريخ النشر 2009
  مجال البحث فيزياء
والبحث باللغة English
 تأليف F. Annibali




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We present a study of the ionized gas in a sample of 65 nearby early-type galaxies, for which we have acquired optical intermediate-resolution spectra. Emission lines are detected in ~89 % of the sample. The incidence of emission appears independent from the E or S0 morphological classes. According to classical diagnostic diagrams, the majority of the galaxies are LINERs. However, the galaxies tend to move toward the Composites region (at lower [NII]/Halpha values) as the emission lines are measured at larger galacto-centric distances. This suggests that different ionization mechanisms may be at work in LINERs.



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